HTTP 103 Early Hints

What does HTTP 103 mean?

An interim response that lets the server send Link headers before the final response is ready. With 103 Early Hints the browser can start preloading CSS, fonts or preconnecting to origins while the server is still generating the page. Chrome, Edge and Firefox support it, and CDNs such as Cloudflare can generate it automatically.

1xx Informational: The request was received and processing continues. Browsers handle these automatically; you rarely see them in DevTools.

103 and SEO

Indirectly positive: faster loading improves Core Web Vitals. Search engines index the final response.

Example response

HTTP/1.1 103 Early Hints
Link: ; rel=preload; as=style

Related status codes

• 100 Continue — The server has received the request headers and the client may send the body.
• 200 OK — The request succeeded and the response body contains the requested resource.
• 304 Not Modified — The cached copy is still valid, so the server sends no body.

Check which status code a URL returns with the HTTP header checker.